The invention discloses a bi-directional electric driving system for an electric vehicle. The bi-directional electric driving system comprises a switching flux motor, a mode control relay, a rectifier filter module, a CUK chopping module, a three-phase H-bridge driving module, a logic control unit and an encoder. Working modes can be switched over by the mode control relay according to different vehicle running states, the three-phase H-bridge driving module works when the electric vehicle is in starting or normal forms, and 48V direct currents of vehicular storage batteries can be converted into alternating currents for driving the switching flux motor to drive the electric vehicle by the aid of control signals provided by the logic control unit; the mode control relay is switched by the rectifier filter module during braking or decelerating, the rectifier filter module works, alternating-current voltages generated by the switching flux motor during reverse towing can be converted into direct currents with certain voltages, and the direct currents are converted into direct-current points with fixed 48V voltages by the CUK chopping module to charge the vehicular storage batteries. The bi-directional electric driving system has the advantages that the electric vehicle can efficiently run in an energy-saving manner according to particular working conditions of the vehicle, and accordingly the driving range of the electric vehicle can be effectively extended.